Hi Tudor, I think you want the "Twist = Flat" option and also use "Set flat direction" along your axis:





The "Twist = Flat" option means the profile will not rotate freely around the rail tangent, it will be limited to only pivot around the "flat direction".

The default "Flat direction" is the world z axis, so when you have some other direction you need to click "Set flat direction" to set it.

Another way you can make this kind of thing is by extruding your profile out straight and then use Transform > Deform > Twist on it.

- Michael